The invention provides a preparation method of TiB reinforced medical porous titanium. The preparation method comprises the steps of weighing Ti powder, TiB2 powder, pore forming materials NH4HCO3 according to a certain proportion first; then uniformly mixing under the protection of argon by using a planetary ball mill; then performing vacuum sintering by using a discharge plasma sintering furnace; and finally, performing vacuum heat treatment so as to obtain the TiB reinforced medical porous titanium with low elasticity modulus, high strength and moderate porosity. According to the preparation method, porous structure design is combined with in-situ spontaneous TiB reinforced phases, so that the elasticity modulus which is close to human bones and the proper porosity can be kept, the mechanical properties of the porous titanium are obviously increased, a small amount of TiB is added, and no biotoxicity exists. The preparation method and process are simple and feasible, the porous titanium with controllable porosity (10 to 60%), low elasticity modulus (10 to 20 GPa), high strength (200 to 1400 MPa, compared with the porous titanium without TiB, the strength of the porous titanium with TiB is increased by one to three times under same parameters) and good biocompatibility can be obtained, and the porous titanium has great prospects and is one of porous materials for hard tissuerepair and replacement in the field of biomedicine.